Should I add or subtract 6 degrees when taking azimuth from a map and setting it on a compass? When a commander tells you "You should walk towards 90° azimuth," should you add or subtract 6 degrees to ...

Abstract: Conventional drill-following measurement systems pass the downhole instrument bus through the drill hole in the drill collar. The effect of magnetic field generated by bus current on ...

A LEADING feature of present-day methods of navigation is the use of tables. There is scarcely any method in use in navigation for which one, and probably many, tables, of more or less practical ...